The present invention is particularly applicable but not necessarily limited to the manufacture of split shell bearings, self-aligning bushings and precision split-ring ball bearing assemblies of the angular contact type incorporating either a single or plural rows of balls and which are particularly adapted for carrying thrust loads, as well as radial loading. Of the foregoing, split-ring ball bearings are suitable for use in turbine engines, torque converters, machine tool spindles, deep well pumps and various high load and/or high speed applications requiring precision performance under conditions in which a combination of radial and thrust loads are encountered. The bearing is also applicable for use in non-precision applications, such as in conveyors, for example, in which greater latitude in the dimensional tolerances of such bearings can be tolerated. In either event, it is conventional in bearings of the foregoing type to split either the inner or outer race or ring member to enable an assembly of the maximum number of balls or antifriction elements, thereby optimizing the load carrying properties and durability of the bearing.
It has been conventional in accordance with prior art practices for manufacturing split-ring bearing assemblies to manually inspect the machined ring sections comprising each split race member in an effort to achieve a substantially identical set of mated ring sections. In spite of the use of modern precision machining techniques, it is ordinarily impossible to effect a mating of identical ring sections, which necessitates a further final finishing such as by grinding of the preliminarily mated ring set. Conventionally, the ring sets are mounted on suitable fixtures and are clamped thereon using a spacer, such as a precision shim, between the abutting faces of the ring sections. The preliminarily matched set thereafter is processed together through all of the final finishing operations including race grinding, land grinding, bore honing, radial clearance measurements, outer ring mating, washing and final packaging. During such processing, the ring sections are held together by various special fixtures, metal straps and wires, in order to permit the necessary finishing operations to be performed and which usually require a removal and remounting or retying on passing from one operation to the next operation. The foregoing tedious, time consuming and costly manufacturing operation is necessary since the individual ring sections comprising the split or sectionalized ring member must be as symmetrical and as identical to one another as possible in order to provide for optimum load carrying capacity, performance and durability.
In spite of the painstaking inspection and measurements made of individual ring sections in an attempt to form matched sets and thereafter the concurrent processing of such sets while positioned on elaborate fixtures, the resultant sectionalized race members produced still are not exactly identical due to the geometric variations that inherently exist in randomly and separately manufactured components, which in turn prevents the attainment of optimum functional properties of the final bearing assembly.
The foregoing enumerated problems associated with the manufacture of precision split-ring bearing assemblies are also present in the manufacture of a variety of precision components of the type including at least one member which is of a sectionalized construction comprised of a plurality of assemblable mated sections which heretofore have required the careful match-mating of individual sections. Exemplary of the foregoing are split thick-walled shell or sleeve bearings and bushings, as well as self-aligning bushings, the latter comprising a bushing member having a spherical periphery slidably disposed within a housing having a conforming spherical seat to permit relative movement therebetween.
In an attempt to overcome the foregoing problems associated with the manufacture of precision sectionalized components, it has heretofore been proposed to machine the precision components as an integral unit or to weld the individual sections together to form an integral unit and after the completion of the precision machining operation, to cut or sever the integral components into the separate sections. The foregoing practices have not received widespread commercial acceptance for a number of reasons, not least of which is the cost associated with the cutting or severing operations, as well as the damage or distortion that is sustained by the separated sections as a result of the separation process.
The present invention overcomes the problems and disadvantages associated with prior art manufacturing processes of precision components, providing not only a precision mating of individual sections, but also providing for a substantial simplification and reduction in costs heretofore associated with such manufacturing operations.